Answer:
2 liters of HBr is needed to completely react with the 50 g of salt.
Explanation:
First of all, we determine the reaction:
2HBr + CaCO₃ → CaBr₂ + CO₂ + H₂O
We need to calculate, moles of carbonate in order to state the stoichiometry (1:2)
50 g . 1mol / 100.08g = 0.499 mol
1 mol of salt need 2 moles of acid to react, according to stoichiometry
Then, 0.499 moles of salt, will react with (0.499 . 2)/1 = 0.999 moles
As we have the [HBr], we can calculate the volume.
M = mol/L → we replace → 0.50 mol/L = 0.999 mol /L
L = 0.999 mol/0.50 mol → 1.99 L ≅ 2L
The formula for boiling point elevation is:
deltaT = (Kb)(m), where m is molality of moles solute per kilogram solvent
1.305 = 3.630m
m = 0.3595 = moles/kg solvent
Since we have 1 g of chloroform solvent, this is equivalent to 0.001 kg.
The number of moles is 103 mg or 0.103 g, divided by the molar mass (MM).
0.3595 = (0.103/MM) / 0.001
0.0003595 = 0.103/MM
MM = 286.51 g/mol
Therefore, the molar mass of retinol is 286.51 g/mol
1. Because that shows that you're a living thing because all living things can respond to stimuli.
2. Because an example of stimuli is a virus. If you couldn't respond to it (by fighting against it) you would probably die.
Hope it helps